Crossflow gurus' please help

[neveredge]

I have a 235 that has an even-fire crank, Flex wheel and CCC heads and I need to know what mods and parts work best with the even-fire. The application is a high ported, high rpm (7500+) motor on an 850lbs. Bullet Super comp. It will be used for Lake racing, drags and maybe even a little fishin. (just one pole in the boat) What is the best tuner for this . I have a GT175 tuner which I think is the same as the standard 235. I also have a very short tuner that was used in drag racing years ago. And the last tuner I have is one that is very long. It is still in my old 2.6xp but I don't think it is the original one because it is so long. My old 2.6xp had an incredible hole shot which I attribute to that tuner, and it was on a heavy Ranger bassboat. Now for Carbs. What are the differences between the 1 3/8 ths carbs. Are the carbs from my GT175 just as good as the ones from my 2.6xp or should I be looking for the smaller carbs? Or even something completely differrent. Racer, if your reading this, I spoke with you several years ago on the phone about this particular set-up when I first started thinking about it and you told me I needed the CCC front half to make the Bullet run good. I've found one but I haven't convinced the guy to sell it yet so what can I do to the intake in the mean time. Thanks for help.

[Riverratt]

after talking the other night to you I am now confused. Can the tuner from the 175 be the same as the 235 if the 235 is the only one that has a bubble back? maybe I miss understood you.

[Forkin' Crazy]

Originally posted by Riverratt
after talking the other night to you I am now confused. Can the tuner from the 175 be the same as the 235 if the 235 is the only one that has a bubble back? maybe I miss understood you.

Must be a later model 175. They are bubble backs.

From what I hear (if I remember right LOL!) the carbs off a 78 235 are the ones to have....:)

[Riverratt]

what was so special about those carbs? were they 1 3/8"

[neveredge]

Will the mods done to this reed block help my performance or will it hurt it?

[neveredge]

another

[Forkin' Crazy]

They are suppose to flow better. I have two sets. Was intending them to go on a CCC intake if I could find one or I did not build one first.

My guess would be that those are Land & Sea 10 port cages, or modified ones. The only reason I would think they were L&S is they have reed stops. I don't think Boyson (sp?) use stops. I don't think they could hurt performance, but I don't think they would help it either, unless used on a modified engine.

:cool:

[neveredge]

These were custom made and I really want to be sure before I put them in my motor. Do you have the ability to build a CCC intake copy? Including the front half that mates to the block? I talked to Wayne Taylor at Madd EFI a couple of years ago and he told me he could build me one but it wasn't gonna be cheap. I know where 1 complete CCC motor is but the guy won't sell it. It is sitting on an old tunnel hull parked in the weeds. I know of a 2.6 powerhead with the CCC front half and intake and I can't get that guy to sell either.

[Forkin' Crazy]

Well, I would have to brush up on my heli arcing....:o

But then I would need one to go by too. I think it could be built with sheet metal, but it might be not enough sugar for a dime...

You know where 2 are???? Man! Time to turn on the bugging device and make a call to him/them once a week!

There isn't anyone close to here with anything like that!

I would love to get my hands on one!

[neveredge]

One is in Florida and the other is in Ohio. Thats all the more I'll say cause I want one of them. The front half that mates to the block is different on the CCC. It is not just the intake thats different. According to some old info I have from Land @ Sea the CCC front is worth 15 ponies at WOT. Have to check with Racer to find out if that is true.

[B.Leonard]

On a stock motor where there is a lot of room under the intake those extra 2 reeds might have room to open and help with flow but on my mod motor there's no room for them to open.

The approach I took on my motor was to remove all excess room under the intake by cutting the intake and case front half. I threw those stock hollow rubber stuffers in the trash and filled in every nook and cranny around the cages with epoxy (the intake and cages are one piece). Then I opened up those 8 port cages to look like an 8 piece cheese slicer or steak fry potato slicer (whichever you prefer :D ). Then filled every corner in the intake tract creating a seamless intake tract from the reeds to the port. No excess room or corners to cause turbulence whatsoever including matching the covers to the ports. Then the whole inside of the crankcase was sandblasted to produce a perfect surface to hold fuel in suspension.

The intake/reeds are so much closer to the crankcase the main bolts had to counter sunk a 1/4" deeper to clear the reeds, cut the intake to clear the flywheel and cut back the opening into the crankase less in order to keep the crank from blowing the reed shut.

My whole theory is to keep the flow (at high rpm) away from the underside of the piston area. The flow should all stay behind the liner (unlike a looper). With this theory you will also find that a smaller scallop on the piston is better, puffer and finger ports will also have little effect. It basically concentrates on the existing crossflow design instead of trying to mix looper and crossflow designs/ performance techniques. So far 7200rpm with stock 235 port timing and incredible acceleration and responsiveness :)

-BL

PS - By making a smaller (more shallow) scallop in the piston, it enables the piston to be much stronger in the skirt area. Especially with lightweight pistons.

[neveredge]

B.L,

I remember you telling me all that and I'm gonna copy your intake mods on my even fire crank motor, but I was wanting to know if they work or hurt, on a standard 2.6XP I am going to put my stock XP back together and I wanted to use these. As my stock motor is already 30 over I don't want to do a lot of mods to it. This is the motor that is on my Ranger bassboat. I'm saving the EFC motor for a light weight drag Bullet. I also wanted to thank you for all the advice.

[B.Leonard]

Running the even fire crank shouldn't be a cause to change anything on the intake side. Those mods will work the same. It's the exhaust side where an even fire motor should differ from an odd fire.

In my opinion, an even fire could take advantage of a crossover between the banks. An odd fire should be treated as 2 inline 3 cylinder motors. Totally separate exhaust to keep the early/late firing of the opposite bank from messing with the scavenging of the opposite bank (in theory).

Either way, just spacing the pulses of the crank evenly will have no power increase alone over an odd. It's when it works in conjunction with other factors like the exhaust where a power increase may be seen.

-BL

[Dr Thunder]

Wouldn't the two extra reeds disturb the flow to the original eight?

[neveredge]

Land @ Sea made something similar to these and they claimed that it added 5+ hp on a stock motor at WOT. I know they used thier dyno to test their products but I don't know if the advertising was all just hype or not.

[mercboy]

EVEN THOUGH THE NAME DOESN'T REFLECT IT, I KNOW A BIT ABOUT OMC CROSSFLOWS. THEIR BIGGEST PROBLEM WAS LACK OF PROPER BALANCE. PEOPLE WILL TELL YOU THAT BELOW CERTAIN RPM'S IT DOESN'T MATTER. THAT'S B.S. hAD A V-4 THAT I SPUN 6500- 7000 FOR YEARS WITH NO REBUILD. RAN AWESOME.
I TOOK OVER 1.5 POUNDS OF RECIPROCATING WEIGHT OUT AND SLUGGED THE CRANK. HUGE DIFFERENCE!!!

ALSO, HAD DIFFERENT REED CAGES. SQUARE OFF THE ENDS OF THE CAGE. BETTER FLOW. JUST REMEMBER, IF THE REEDS AND CARB FLOWS 200 CFM BUT THE MANIFOLD ONLY FLOWS 150 CFM, LARGER ANYTHING WON'T MAKE A DAMN BIT OF DIFFERENCE.

NOT REAL FAMILIAR WITH OMC TUNERS, BUT I'M SURE THE GENERAL RULES STILL APPLY, LONGER FOR LOW END, SHORTER FOR TOP END.

LOTS OF HEAD WORK CAN BE DONE AS WELL BUT REQUIRES A GOOD MACHINIST AND LOTS OF PATIENCE.

GOOD LUCK!!
EMAIL- [email protected]

[mercboy]

ALSO, 78 235 CARBS WERE ACTUALLY 1 15/32. ABOUT .090 LARGER THAN THE 1 3/8. WORKED WELL WHEN TUNED RIGHT but EARLY TOP LOADER CARBS HAD A LITTLE BETTER THROTTLE RESPONSE.

[email protected]

[mercboy]

EVEN THOUGH THE NAME DOESN'T REFLECT IT, I KNOW A BIT ABOUT OMC CROSSFLOWS. THEIR BIGGEST PROBLEM WAS LACK OF PROPER BALANCE. PEOPLE WILL TELL YOU THAT BELOW CERTAIN RPM'S IT DOESN'T MATTER. THAT'S B.S. hAD A V-4 THAT I SPUN 6500- 7000 FOR YEARS WITH NO REBUILD. RAN AWESOME.
I TOOK OVER 1.5 POUNDS OF RECIPROCATING WEIGHT OUT AND SLUGGED THE CRANK. HUGE DIFFERENCE!!!

ALSO, HAD DIFFERENT REED CAGES. SQUARE OFF THE ENDS OF THE CAGE. BETTER FLOW. JUST REMEMBER, IF THE REEDS AND CARB FLOWS 200 CFM BUT THE MANIFOLD ONLY FLOWS 150 CFM, LARGER ANYTHING WON'T MAKE A DAMN BIT OF DIFFERENCE.

NOT REAL FAMILIAR WITH OMC TUNERS, BUT I'M SURE THE GENERAL RULES STILL APPLY, LONGER FOR LOW END, SHORTER FOR TOP END.

LOTS OF HEAD WORK CAN BE DONE AS WELL BUT REQUIRES A GOOD MACHINIST AND LOTS OF PATIENCE.

GOOD LUCK!!
EMAIL- [email protected]